Optimizing support acidity of NiMo catalysts for increasing the yield of benzene, toluene and xylene in tetralin hydrocracking

To enhance the yields of benzene,toluene,and xylene in tetralin hydrocracking,the effect of the support acid properties of NiMo catalysts on hydrocracking performance of tetralin were investigated in this study.NaY zeolites were modified by hydrothermal treatment to form USY zeolites at different temperatures and adjust the type and amount of acid.In addition,H-Beta was loaded into the USY to further adjust the acidic properties of the catalysts.The result shows that when the total B acid content of the catalyst is maintained between 150 and 200μmol·g^(-1),the total acid amount is maintained between 1.7 and 1.9 mmol·g^(-1),and the L/B(L and B acids)ratio is maintained between 1.5 and 2,the catalysts have favorable performances on tetralin hydrocracking.Under this condition,the catalysts have a yield of benzene,toluene,and xylene higher than 30 wt%and a selectivity for benzene,toluene,and xylene higher than 35%.The tetralin conversion is greater than 85 wt%.The AB6 catalyst obtains the best hydrocracking effect with the conversion of tetralin reaching 90.24 wt%,the yields of benzene,toluene,and xylene reaching 33.58 wt%,and the selectivity of benzene,toluene,and xylene reaching 37.21%,respectively.

Study of ground ozone and precursors along with particulate matter at residential sites in the vicinity of power plant

Emission source characterization and meteorological influence are the key aspects to gain insight into the ground ozone governing mechanisms.Receptor-based data analysis techniques help in comprehending local ozone fluctuations in the lack of accurate information on the emission characteristics.Through sophisticated data analysis,the current study offers insight into the key factors influencing the ozone changes in the vicinity of power plants.Ground ozone(O_(3))and its precursor variables carbon monoxide(CO),nitric oxide(NO),nitrogen dioxide(NO_(2)),Sulphur dioxide(SO_(2)),benzene,toluene,ethyl-benzene and xylene(BTEX)along with the particulate matter of size less than 10 and 2.5 micron(PM_(10) and PM_(2.5))and meteorological variables have been studied at a residential site near the coal-fired power plant in the two cities;Chandrapur and Nagpur during 2016–2019.O_(3) is observed to be not correlated significantly(r<0.16 and<0.1 in Nagpur and Chandrapur,respectively)with any of its precursor variables in two cities.On a finer time scale,however,an association of O_(3) with CO,NO,NO_(2) and BTEX suggested that the O_(3) formation mechanism is driven by volatile organic compounds(VOCs)(mainly BTEX),CO and NO_(x).On the coarser scale,however,seasonality and other factors have distorted the correlation.Random forest model with O_(3) concentration as the response variable and NO_(2),NO,SO_(2),CO,BTEX,PM_(10) and PM_(2.5) as independent variables suggested that PM_(10),NO,CO and solar radiation are highly important variables governing the O_(3) dynamics in Chandrapur.In Nagpur,wind direction,relative humidity,temperature,toluene and NO_(2) are more important.Qualitative analysis to assess the contribution of emission sources suggested the influence of traffic emissions in Nagpur and the dominance of non-traffic related emissions,mainly power plant and mining activities in Chandrapur.The hazard quotient is observed to be>1 in both cities suggesting a health hazard to the residents living in the area.